We randomly assigned 4589 healthy nulliparous women who were 13 to 21 weeks pregnant to receive daily treatment with either 2g of elemental calcium or placebo for the remainder of their pregnancies. Calcium supplementation did not significantly reduce the incidence or severity of preeclampsia or delay its onset. Additional analyses utilizing the study database and specimen repository are being performed. During FY10 papers were published on the relationship of preeclampsia and soluble fms-like tyrosine kinase 1 to the development of reduced thyroid function, the correlation of angiogenic factor abnormalities with spontaneous resolution of preeclampsia following intrauterine death of one twin, on first trimester prediction of early preeclampsia, on circulating angiogenic factors in gestational proteinuria without hypertension, on smoking and preeclampsia, and on the use of angiogenic biomarkers to distinguish non-HELLP related thrombocytopenia from HELLP syndrome. Work on angiogenic factors and preeclampsia is continuing.